Work holding chuck



Jan. 15, 1952 A. E. CHURCH 2,582,680

WORK HOLDING CHUCK Filed Jan. 14, 1948 V, Sv INVENTOF-z /g AE. CHURCH l 1 f 4 BQM ATTORNEY Patented Jan. 15, 1952 Albert .E...Churcl 1, New Britain, Conn., assignor to Union Manufacturing Company, NeWBritain, Conn., a corporation of' Connecticut Application/January: 14, 1948; Serial No.2,2995- (clears- 4) f 2 Claims.

This invention relates; work Aholding chucks adapted .for application ito` machines inwhich. the workpiece is requiredto berotated uponI agiixed axis-.

dMore particularly.. ,the .invention :relates to Aa:

work holding chuck of the diaphragm type,the exingfofvthe diaphragmfbeing usedtowopen and close thejaws slightly relative .-tothe work piece to release or agripthe work piece.

A, primaryvlobjectof` .the inventiontis to. pro-f vide improved operating means for a diaphragmA chuck. 4by means of. -airfor other elastic fluid admitted to the spindle at its end remote from the chuck.

, /Another objectcf the.` inventonistoprovide an expansible Vimpervious yb'aggwithin. the chuck body member into whichfiiidunde'r pressure maybe admitted-ftey eXp'a-ndfthe bag and deectfthe diaphragm to :which the chuck 'jaws arev attached, the flexing of Vlrtlie-1diaphrag1fn =by expanding the bag serving to `forcevthe jaws. into gripping contact with the workfpiece.

With.:the.above and other objects in `*view-tbe invention includes the features -of construction and operation set forth in the following specification and illustrated in the accompanyingsdrawing.'V

In the accompanying drawing annexed hereto and forming a part of this specification, I have shown the invention embodied in a lathe or other machine tool spindle but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope of the invention,

the claims appended to this specification being relied upon for that purpose.

In the drawing:

Fig. 1 is a central longitudinal section through a chuck made according to the present invention;

Fig. 2 is a fragmentary front view of the chuck shown in Fig. l, and

Fig. 3 is a detail view of one of the parts forming the chuck.

In the above mentioned drawing, there has been shown but one embodiment of the invention'which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly, and in its preferred aspect, the invention may include the following principal parts: First a chuck body; second, a slightly flexible metal diaphragm; third, chuck jaws fixed to said diaphragm; iourth,';anexpansible impervious.

bag within thechuck body; fifth, a-movable memberradjacent'the bag; sixth,. means connecting the diaphragm andv movable membervso that movement of the-member flexes the diaphragm, and .seventh,f uid r.admitting meansf to' theexpansible bagqduring rotation ofthe chuck:

Referring` more'indetail tothe figures ofthe drawing thereis shown a chuck body'comprising.-

a'disky I0 to Which;.;is--fixedly'attached va-hea or .end1:piece.: I 2 in. :a mannerv :to form. a.'v short cylindrical Aopening :between their .adjacent sur.-u

faces. On the v oppositefside of the disk.v I0 is. ai diaphragmrlll*attached-at itszperiphery to thevr rimpfjthe disk III byfmeans oli-.elongated screws Il.- As4 shown-in Fig. :1, screws. I 6 retain-.imxedz relationtheendpiecewI2, the :fdisk: I0 and thediaphragmz. t4..v The jaws i I8 Vareaattachedl to;`

the diaphragm I4 by the threaded ends 'of screws IIi.I and. byr'additional screws 1.20:. By.;this= con structionapthe members formingthechuck are heldlin; position and-:so that the diaphragm I4 may ex. .slightly and radiallyy movethe work. engaging portions of 1: the jaws I 8.1 The .chucki f, is 'mounted for'rotationon. a hollowl spindlesuch; as; shown: at 2 2 by :engagement-with: the; spindleI by internal threads on the end piece I2.

The jaws I8 preferably may be formed from an annulus having the same outer diameter as the disk I0 and diaphragm I4 by slitting the annulus radially into as many individual jaw members as desired. Each of the jaw members I8 is secured to the diaphragm I4 by screws I6 and 20 and the work engaging surfaces of the jaws is machined to lit the particular work piece W being operated on. y

Toflex the diaphragm I4 to tighten the jaws I8 upon work piece W fluid pressure means are employed. Within the recess formed between the disk I0 and the end piece I2 is a plate 24 attached at its center to the diaphragm I4 by a stud or bolt 26. Between the plate 24 and the disk I0 is an annular expansible impervious bag 28 preferably made of rubber or other similar material. This bag 28 as shown surrounds the stud. 26 to which portions of the bag may be sealed and substantially iills the recess between disk I0 and plate 24. By admitting air or other gas under pressure to the interior of the 3 is being applied to the plate 24 and diaphragm and the jaws are open to permit work pieces to be inserted.

To admit air or other iiuid under pressure to the interior of the bag'28 to ex the diaphragm I4 and grip thework piece W by the jaws openings or conduits are provided within the stud 23 which in turn communicate With an elognated tube 30 extending to the tail end of spindle 22.A

An end piece 32 is inserted within the spindle 22 and an opening 34 therein communicates with the tube 30 to which member 32 may be secured in uid tight relation. Surrounding the extended fixed wally of said chuck, means to admit iiuid portion of member 32 is a sleeve 36 rotatable onI the member 32 by suitable anti-friction bearings 38. A iiuid supply line 40 may be attached to the sleeve 36 permitting uidto enter the open- ,l ing 34' within member 32 and through tube 3D into the interior of bagv 28. To maintain fluid tight relation between the member 32 and the sleeve'36 cup Washers'fl2 `are inserted'between the sleeve and end member on either side of the opening 34 and bearing against the adjacent end surfaces of the bearings.V

To connect the inflatable bag 28 to the stud 2liq a ring 29, provided 'with an annular recess 3l formed -within itsV inner surface and suitable radialopeningsfmay be mounted on an intermediate surface. The recess 3l permits "air under pressure to Vpass from the tube 30 through the stud 26 and to the space within the inflatable` bag. The end of'the tube 30 entering stud 23 may be sweated` therein or otherwise sealed tothe stud in pressure tight relation. ABy means'ofl a suitable nut on'the inner end of the stud plate 24 is held lfirmly in positionand retains the sur'- faces of the bag in pressure tight relation to the surfaces of the ring 29 which is disposed between the surfaces of the bag.

The opposite end of the tube 30 maybe fitted into the end piece 32 in a manner to permitmove'- ment of the tube axially relative to the end 'pie'ce as the diaphragm I4 is vflexed by admission .or exhaustion ofv theair to and from the bag 28.

For this purpose a packing 33Jmay be'placed' around the tube 30v Within the end piecev32, this member, a diaphragm therein,

underpressure to saidbag to displace said movable plate and ex said diaphragm, whereby said jaws are moved to work gripping position, and

means to return said diaphragm to inoperative position when pressure within the bag is released.

2. A work engaging chuck comprising a body chuck jaws secured to said diaphragm and movable to work gripping position when said diaphragm is ilexed, a fixed disk .withinvsaid chuck, an axially movable member attached centrally to said diaphragm, an annular impervious inflatable bag disposed' between said xed disk and movable member whereby iniiating said bag displaces said movable member from said fixed disk and lflexes said diaphragm, and means at the end of the spindle mounting said chuck to admit fluid underpres-l sure t0 Within said bag during rotation of said chuck.

REFERENCES CITED The following referencesv are of record inthe.4

iiie of this patenti Y, u d

v UNITED STATES PATENTS' Date Number A Name l 1,389,272 Scaife Aug. 301,` 192i 1,956,318 Draper w Apr. 24, 1934 2,267,815 Bush Dec. 30, 1941 '2,376,475 Bush May 22211945 2,389,366 Jones y Nov. 20,1945y 2,396,521 Mead v Mar. 12,'1946 2,428,496 MeadV Oct: 7, 1947 ALBERT E. CHURCH,

Hohwart et al. Dec. 20, 1949v 

